Junos OS (SRX firewalls)
CVE-2025-30658: SRX Series: On devices with Anti-Virus enabled, malicious server responses will cause memory to leak ultimately causing forwarding to stop
A Missing Release of Memory after Effective Lifetime vulnerability in the Anti-Virus processing of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS (SRX Series) 0 | 21.2R3-S9 or later |
| Junos OS (SRX Series) 21.4 | 21.4R3-S10 or later |
| Junos OS (SRX Series) 22.2 | 22.2R3-S6 or later |
| Junos OS (SRX Series) 22.4 | 22.4R3-S6 or later |
| Junos OS (SRX Series) 23.2 | 23.2R2-S3 or later |
| Junos OS (SRX Series) 23.4 | 23.4R2-S3 or later |
| Junos OS (SRX Series) 24.2 | 24.2R2 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A Missing Release of Memory after Effective Lifetime vulnerability in the Anti-Virus processing of Juniper Networks Junos OS on SRX Series
allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).
On all SRX platforms with Anti-Virus enabled, if a server sends specific content in the HTTP body of a response to a client request, these packets are queued by Anti-Virus processing in Juniper Buffers (jbufs) which are never released. When these jbufs are exhausted, the device stops forwarding all transit traffic.
A jbuf memory leak can be noticed from the following logs:
(<node>.)<fpc> Warning: jbuf pool id <#> utilization level (<current level>%) is above <threshold>%!
To recover from this issue, the affected device needs to be manually rebooted to free the leaked jbufs.
This issue affects Junos OS on SRX Series:
- all versions before 21.2R3-S9,
- 21.4 versions before 21.4R3-S10,
- 22.2 versions before 22.2R3-S6,
- 22.4 versions before 22.4R3-S6,
- 23.2 versions before 23.2R2-S3,
- 23.4 versions before 23.4R2-S3,
- 24.2 versions before 24.2R2.
Am I affected?
To be exposed to this issue the device needs to be configured with Anti-Virus:
[ security utm utm-policy <name> anti-virus ]
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.